Timing belt woes...

[Iridium]

I'm helping out a friend doing a timing belt on his 88 Accord LX, somehow he stripped 49 teeth off the belt...yes, I counted. Problem is this; he had his clutch done awhile back and they replaced the flywheel with an aftermarket flywheel with only 1 notch mark on it, presumably the TDC notch for timing belt changes. Here's where things get odd, the notch is exactly 180 degrees off of TDC which I verified by pulling the oil pan and setting the crank at TDC and BDC and match marking the relative positions. Is it possible on the older Accords to install the flywheel in whatever position you want or are they keyed to only install in one specific way? My friend needs their car back asap and I'm at a loss except to just use my own marks and set it based off the cranks position.....

[Demon1024]

Did you check the valve position to make sure it was on the compression stroke? I'd set it from tdc and mark the flywheel and go from there. Unfortunately I'd bet you hit some valves when the belt went. I'd honestly free spin it with out spark plugs to make sure nothings gonna jam with the new belt on and give it at least a cold compression test. I was wrong about lobe position now that i think about it... but both valves should be closed either way

[Hazwan]

I know the flywheel is keyed so its impossible to put it wrong

[Iridium]

At this point I guess I'm going to ignore the mark on the flywheel, set TDC based off the actual piston/crank/rod relationship then set the cam timing per stock marks and hope for the best.

[cygnus x-1]

The flywheel is keyed to the crank. No chance of it being backwards unless one of the bolts was left out or something. Looking at the pistons is the best way to find TDC without the flywheel. Especially with the oil pan off you should be able to eyeball it within a few degrees, which should be good enough.

Something else you could try just for secondary verification is to count the teeth on the flywheel and divide that by 2. The TDC position should be that many teeth away from the mark (assuming that mark really is 180 degrees off).

C|

[niles]

Make sure to manually rotate the engine by the crank pulley to make sure the valves clear the pistons after you've got it all together.

[Dr_Snooz]

These aren't interference engines. The valves will be fine.

[Iridium]

So I did a whole bunch of referencing at various points on the crank and flywheel, triple checked my numbers and I'm 99.9% sure I got it figured out, we'll see tomorrow but worse case its only a single tooth either way, easy to fix since I only installed the Water Pump/Alternator belt

[niles]

These aren't interference engines. The valves will be fine.

That's good, I've heard both about our engines, so I always follow the manual's procedure.

[Buzo]

What happened is that you set the cylinder 1 as DTC when it was supposed to be in the expulsion cycle and not in the compression cycle.
That's why the mark is 180 degrees away.
Remove your timing belt, bring the mark in the flywheel to where you can see it through the timing adj. hole. Now you are at DTC @ the compression cycle.
Set the TDC timing in your camshaft and put back the timing belt.

[Iridium]

I was timing only the bottom end as the belt stripped its teeth, all the actual timing of valve opening/closing/firing comes from the head and valvetrain being timed off the crank which doesnt care whether its a compression or exhaust stroke, the piston is moving up or down and TDC is TDC. Suffice it to say it runs great, better than before according to my buddy.

[Dr_Snooz]

I had thought of that too Buzo. The reality is that the crank is only at TDC once per revolution, so if he's 180 deg. off on the crank, he's 180 deg. off. Compression and exhaust stroke differences come because the crank rotates twice for each revolution of the cam. I'll confess that I spent some time scratching my head over that one on a timing belt replacement I did years ago.

It's going to be a real bear fixing this. I'm not sure how you do it without dropping the trans and scribing proper marks on the flywheel. Even if you get the timing belt back on, setting the timing properly will still be a problem, unless you do it old school with a vacuum gauge or something. When I did my MT swap, I got a new flywheel without any marks at all. I was able to fix it by aligning the new one up with the old one and engraving marks while I had everything apart. That becomes much more challenging after everything is installed again.

Just another reason I don't let others work on my car.

[2oodoor]

Im going to be a wise geek and say if it were truely 180 out why not swap the wires 1 to 4/ 2 to 3? :/

[Demon1024]

Lol then the next person would have to deal with that too